One of our cats doesn't just test the water with her foot. She puts one foot right down to the bottom of the bowl and stands on it. It's a mix master bowl, about 4 quarts I'd guess. You know they are about as deep as they are wide. It seems she likes to drink from the side opposite to where she is standing and has to stand in the bowl to get close to the opposite side.
And No, I know what you are all thinking, a smaller bowl doesn't cut it, she likes this one.
Glad your kitty's vision checked out all right.